﻿//  Copyright 2016 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

using NtApiDotNet;
using System;
using System.Management.Automation;

namespace NtObjectManager.Cmdlets.Object
{
    /// <summary>
    /// <para type="synopsis">Sets a registry key value.</para>
    /// <para type="description">This cmdlet sets a registry key value on a specific key.</para>
    /// </summary>
    /// <example>
    ///   <code>Set-NtKeyValue -Key $key -String "Hello"</code>
    ///   <para>Sets the default value to the string "Hello".</para>
    /// </example>
    /// <example>
    ///   <code>Set-NtKeyValue -Key $key -Name ABC -MultiString "Hello","World!"</code>
    ///   <para>Sets the value ABC to the multi-string "Hello" and "World!".</para>
    /// </example>
    /// <example>
    ///   <code>Set-NtKeyValue -Key $key -Name ABC -ValueType Binary -Bytes @(1, 2, 3, 4)</code>
    ///   <para>Sets the value ABC to the binary data value.</para>
    /// </example>
    [Cmdlet(VerbsCommon.Set, "NtKeyValue")]
    public class SetNtKeyValueCmdlet : PSCmdlet
    {
        /// <summary>
        /// <para type="description">The key to set the value on.</para>
        /// </summary>
        [Parameter(Mandatory = true, Position = 0)]
        public NtKey Key { get; set; }

        /// <summary>
        /// <para type="description">The name of the value to set. If not specified it will set the default value.</para>
        /// </summary>
        [Parameter(Position = 1)]
        public string Name { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as a string.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromString")]
        public string String { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as an expanded string.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromExpandString")]
        public string ExpandString { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as a string.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromMultiString")]
        public string[] MultiString { get; set; }

        /// <summary>
        /// <para type="description">Specify the value type when using bytes.</para>
        /// </summary>
        [Parameter(ParameterSetName = "FromBytes")]
        [Parameter(ParameterSetName = "FromString")]
        public RegistryValueType ValueType { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as an array of bytes.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromBytes")]
        public byte[] Bytes { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as a dword.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromDword")]
        public uint Dword { get; set; }

        /// <summary>
        /// <para type="description">Specify whether to set the dword as big endian or little endian.</para>
        /// </summary>
        [Parameter(ParameterSetName = "FromDword")]
        public SwitchParameter BigEndian { get; set; }

        /// <summary>
        /// <para type="description">Specify the value as a qword.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromQword")]
        public ulong Qword { get; set; }

        /// <summary>
        /// <para type="description">Specify the value from an existing NtKeyValue. The name is ignored.</para>
        /// </summary>
        [Parameter(Mandatory = true, ParameterSetName = "FromValue")]
        public NtKeyValue Value { get; set; }

        /// <summary>
        /// Overridden ProcessRecord method.
        /// </summary>
        protected override void ProcessRecord()
        {
            switch (ParameterSetName)
            {
                case "FromString":
                    if (ValueType == RegistryValueType.None)
                    {
                        Key.SetValue(Name, String);
                    }
                    else
                    {
                        Key.SetValue(Name, ValueType, String);
                    }
                    break;
                case "FromExpandString":
                    Key.SetValue(Name, RegistryValueType.ExpandString, ExpandString);
                    break;
                case "FromMultiString":
                    Key.SetValue(Name, MultiString);
                    break;
                case "FromBytes":
                    if (ValueType == RegistryValueType.None)
                    {
                        ValueType = RegistryValueType.Binary;
                    }
                    Key.SetValue(Name, ValueType, Bytes);
                    break;
                case "FromDword":
                    Key.SetValue(Name, BigEndian, Dword);
                    break;
                case "FromQword":
                    Key.SetValue(Name, Qword);
                    break;
                case "FromValue":
                    Key.SetValue(Name, Value.Type, Value.Data);
                    break;
                default:
                    throw new ArgumentException("Invalid type specified");
            }
        }
    }
}
